Freshwater Ascomycetes - Species Monograph

Click on the pictures below to view them at their full size.

Genus	Species	Author
Ocala	scalariformis	Raja & Shearer
Class	Order	Family
Dothideomycetes	Pleosporales	Inc. sed

Genbank ID: 741143 MycoBank ID: 512704

Synonymy:

Description

Habit:

Ascomata scattered on decorticated woody debris collected from a lake.

Ascomata:

Ascomata on wood 165–195 × 130–138 µm, brown to dark brown, semi-transparent, superficial to immersed, scattered, globose to subglobose, membranous, ostiolate, with a short papilla.

Peridium:

Peridial wall membranous, composed of cells forming a textura angularis to epidermoidea in surface view; cells 10–15 × 2–5 µm.

Beak:

Papilla 15–25 × 10–15 µm; aperiphysate.

Hamathecium:

Pseudoparaphyses 25–35 × 5–8 µm, sparse, broad, hyaline, septate, slightly constricted at the septa, branched.

Ascus:

Asci 140–200 × 18–26 µm (mean = 168 × 22 µm, n = 20), obclavate-fusoid, bitunicate, fissitunicate; ectoascus rupturing at the ascus apex, fasciculate, with a flattened apex, containing eight overlapping to obliquely biseriate ascospores, pedicellate; pedicel tapering to a fine point.

Ascospore:

Ascospores 38–45 × 9–10 µm (mean = 42 × 10 µm, n = 25), 9–12 septate, hyaline, narrowly ellipsoidal to fusiform, slightly curved, thick-walled, accumulating at the tip of the papilla to form a white mass on the substratum, with amorphous apical appendages.

Sheath:

Not observed.

Appendage:

Appendages ephemeral, amorphous bipolar gelatinous ca. 2–5 × 4–7 µm, staining blue in aqueous nigrosin, extending in water, not visible in glycerin and lactic acid.

Culture:

Unable to culture fungus.

Anamorph:

Not observed.

Other info

Type & Location:

UNITED STATES. FLORIDA: Ocala National Forest, Mary Lake, 29°4' 20.8"N,81°49'57.8"W, water temperature 30C, pH 5, on submerged decorticated woody debris, 16 July 2006, Huzefa A. Raja and J.L. Crane, F121-1 (HOLOTYPE ILL40593).

Other Specimens:

Substratum:

Submerged woody debris.

Habitat:

Lentic

Distribution:

USA (Florida)

Pertinent Literature:

Raja, H.A., Ferrer, A. and C.A. Shearer. 2009.

Comments:

Additional Pictures

Stained with aqueous nigrosin.
Ascus.
Discharged bitunicate asci.
Asci and pseudoparaphyses.
Asci and ascospores.
Immature ascus.

Back